Railway-gate



(No Model.)

A. J. MCDONALD. RAILWAY GATE.

No. 447,080. Patented Feb 24,1891.

UNITED STATES PATENT OFFICE.

ALEXANDER J. MCDONALD, OF CHICAGO, ILLINOIS.

RAI LWAY-GATE.

SPECIFICATION forming part of Letters Patent No. 447,080, dated February 24, 1891.

i Application filed April 15, 1890. Serial No. 347,992. (No model.)

To all whom it may concern.-

Be it known that I, ALEXANDER J. MCDON- ALD, a citizen of the United States, residing at Chicago, Illinois, have invented certain new and useful Improvements in Railway-Gates, of which the following is a specification.

The present invention relates to gates operated by air or similar power; and its object is to improve in several particulars upon the construction shown and described in various patents obtained and applications filed by me.

My improvements relate more especially to the lock for holding the gate in position, the bumper for preventing shock when the gate is raised or lowered, the quadrant to which the operating-chains are fastened, and to the construction of the gate-arm; and the invention consists in the features and details of construction hereinafter described and claimed.

In the drawings, Figure 1 is a vertical central section through the posts of a pair of gates provided with my improvements, and

Fig. 2 a plan view of a portion of Fig. 1.

A A are the posts; '13 B, the-gate-arms; O C, the sidewalk-arms; D D, the operatingchains attached to the double quadrantD. d is the shaft on which this quadrantis mounted; E, the operating-cylind er 5 E, the piston therein, the piston-rod e of which is connected to the quadrant D by means of a suitable arm e.

F F are gear-wheels for communicating motion of the shaft (1' to the sidewalk-arms C O.

G is a ratchet-wheel mounted on the shaft 61; G, a toothed bar engaging with such wheel; g,a hook engaging with the end of the bar G; H, a small cylinder and piston; II, pipes for supplying steam or air to the cylinders; I, a double-headed bumper attached to the quadrantD; J, a yoke in which the gatearm B is mounted, and j j pins passing through the yoke and engaging with the gate-arm.

The gate-post, operating-cylinder, chains, gear-wheels, sidewalk-arms, and also the roadarms, except so far as hereinafter specified, are made in the usual manner, and, being well known, require no further description. I then construct what I term a double quadrant D, preferably of the shape shown in the drawings. This is mounted on the shaft cl, and the operating-chains are fastened, as shown, to the upper ends of the quadrant, so that as the shaft is turned the chain will be wound up, the pull being constantly tangential to the surface of the quadrant. To this quadrant I connect the rod of the operatingpiston by means of a suitable bar or arm e, so that as the piston rises and falls the quadrant is. rotated with its shaft to open or close the gate-arms. To this quadrant is attached in any manner a bumper I. This consists of a double-headed bolt 1', passing through a hole in an extension of the quadrant and provided, as shown,with spiral springs 'i. This bolt is free to slip back and forth when sufficient force is exerted to overcome the tension of the springs. At suitable points on the interior of the posts A A, I provide buffers I, consisting, preferably, of a bracket supporting a block of rubber. As the quadrant swings from side to side the bolt-heads will strike against these buffers, and the action of the buffers and the spiral springs *6 together will prevent any shock that might otherwise occur through the motion of the arms. On the shaft d is anotched segment, and a toothed bar or arm G, fulcrumed inside of the post, engages with this segment to lock the gate in various positions. Owing to the jars consequent upon the operation of this gate the arm is apt to be thrown out of engagement with the segment, allowing the gate-arm to fall. To obviate this I provide the hook or lock 9, pivoted inside of the post and engaging, as shown, with the upwardly-inclined end of the arm G. To disengage this hook, I provide a small cylinder H, the piston-rod h of which strikes as it rises against a projection g on the hook and raises the hook to disengage the arm, and then also raises the arm to release the segment. When the gate is to be lowered and the air-pressure in the cylinder H ceases, the piston therein will fall and allow the arm to engage with the segment to lock the gate-arms and the hook g to engage with the end of the arm to lock that.

IVhen the arms B B are lowered, itvfrequently happens that teams drive against and break them. To prevent this I mount each of these arms in a yoke J upon a pin j, so as to allow them to rotate, as shown in Fig. 2. To hold them in the proper normal position, I provide a pin j, passing through the yoke and the end of the arm B. This pin is strong enough to hold the gate-arm while being raised and lowered, but shouldbe so constructed that when a team drives against the arm the pin will break, allowing the arm to swing sidewise into the position shown in Fig. 2, thus preventing it from breaking.

I claim- I 1. In a railway-gate, the combination of a toothed segment G, an arm G, engaging therewith, a hook g, engaging with the arm to lock the same, and means for raising such hook and arm, substantially as described.

2. In a railway-gate, the combination of a double quadrant D, a double-headed bolt 17, mounted therein, springs a" on each bolt, and blocks I against which the bolt strikes as the quadrant is rocked in one direction or the other, substantially as described.

3. In a railway-gate, the combination of a yoke J, an arm B, swinging therein, and a pin 3', passing through the yoke and arm, holding the arm as it is raised or lowered, but breaking when sufficient force is applied to the arm, whereby the latter is allowed to swing around and kept from breaking, substantially as described.

ALEXANDER J. MCDONALD. Witnesses:

GEORGE S. PAYSON, SUSIE CROWLEY. 

